This investigation into the pre-neural events in taste reception seeks to define the stimulus-receptor interaction and the response of the taste cell following this reception step. Binding of taste ligands to defined homogenate fractions is being characterized to determine if the characteristics of this homogenate-ligand interaction are consistent with a receptor hypothesis. Salt interactions with taste receptor cell membranes are being modeled with a mixed liposome system where perturbations are quantitated by observing changes in fluorescence of dyes incorporated into the lipid matrix. Metabolic activity of the taste cell is being monitored by observing the level of reduced pyridine nucleotide fluorescence in taste buds during stimulation. Quantitative fluorescence microscopy is being employed.